Bio-inspired prokaryotic array for fault-tolerant electronic systems

Samie, M.
(2012)
Bio-inspired prokaryotic array for fault-tolerant electronic systems.
PhD, University of the West of England.
Available from: http://eprints.uwe.ac.uk/16539

Full text not available from this repository.

Abstract/Description

Integrated circuits and electronic systems fabricated in current technologies suffer from a wide range of faults that may occur during the fabrication process or during the life time of each circuit/device. Soft (non-persistent) faults are caused mainly by ionizing radiation. It is known that the rate of soft faults increases and the rate of hard faults decreases as technology improves. It is therefore vital to build systems able to tolerate faults, especially in order to improve the reliability of critical applications, such as systems working in extreme environments, satellites, aircrafts, medical instruments etc. Self-healing and fault-tolerant systems deal with faults through mitigation, self-test and self-repair mechanisms. A number of designs have already been proposed to improve reliability. The bio-inspired approach to self-healing systems is part of a very promising class of methods that try to mimic the successful reliability solutions found in living organisms to design self-healing electronic systems.
This project aims to further our understanding of how the unicellular nature of biological systems and their protective immune systems could be used to enhance reliability of digital electronic systems. A novel model, which takes inspiration from unicellular living entities (prokaryotes) to reduce the large hardware and software overhead found in current bio-inspired multi-cellular systems, is proposed and implemented in an architecture named Unitronics (Unicellular + Electronics). Unitronics proposes the application of mechanisms that take place during bacterial biofilms formation to improve the reliability of electronic systems. Concepts characteristic to bacterial formation, such as geometry of islands, void and cell, are used to define the prototype of Unitronics-based applications in the hardware layer. Each cell includes configuration information that defines the cell’s phenotype once it has been programmed. Finally, other prokaryotic features such as bacterial species, transposone, horizontal and vertical gene transfer functions (HGT-VGT) define the genotype of Unitronics systems, and are used to evolve, test and repair cells within a community. A single cell is not able to repair itself; instead the cell includes just its own configuration bits. A faulty cell is repaired based on its similarities and differences to/from other cells within a community of cells. This method has several advantages, such as: balance between time and hardware redundancies; possibility of repairing several faulty cells at the same time; and compression of redundant information needed for fault recovery.
Several applications (including an e-puck object avoidance robot controller, signed and unsigned multipliers, and PID controller) are used to demonstrate the underlying theory and the practical viability of our bio-inspired model, and to show examples of performances that can be achieved using the Unitronics architecture we have proposed.